I say kill it with kindness or do it as well to them. unless its physical, respond to his/her smart remarks with even smarter ones. They'll learn to back off. OR talk it out, see whats the deal. is it harmless joking around? or is this a straight up a**hole? try to figure that out before you get defensive. Use your cool water, to take out their fire. You'll be respected once they see your not able to be pushed around. I'm sure a bully wouldn't bully someone he/she knows is tougher than them, or stronger than them.